code: def test_3_get_columns(self):
      columns = self.handler.emails.get_columns()
  
      expected_columns = [
          "id",
          "message_id",
          "thread_id",
          "label_ids",
          "sender",
          "to",
          "date",
          "subject",
          "snippet",
          "body",
      ]
  
      self.assertListEqual(columns, expected_columns)
  
file_path: mindsdb/mindsdb/integrations/handlers/gmail_handler/tests/test_gmail_handler.py
imports: from mindsdb.integrations.handlers.gmail_handler.gmail_handler import GmailHandler
  from mindsdb.api.executor.data_types.response_type import RESPONSE_TYPE
  import unittest
label_desc: Use image node_id 5 for calling the EmailsTableTest obj's underlying member method code with example usage: obj.test_3_get_columns() without return types